Ms Chua applied to annul the marriage in February 2011 on the grounds that Mr Chai refused to consummate the marriage, according to court documents.

An interim judgment was made in her favour, but Mr Chai applied to have it set aside. Eventually, the marriage was declared void by the High Court due to the fact that it was not between a man and a woman.

The couple are still engaged in a court battle to split their matrimonial assets.

Ms Chua claimed in her submission that she never knew her husband used to be a woman, until she received the interim judgment to annul their marriage.

Mr Chai claimed that he told her before they got married that he could not consummate the marriage, or have children with her.

It was unclear whether he told her he had undergone a sex-change operation.

In March 2009, they bought a condominium in Jurong West together. They have been tussling over the apartment, estimated to be worth $1.3 million.

Ms Chua said that Mr Chai insisted he be named the co-owner of the property as a condition for marrying her. She also said he had been borrowing money from her while they were dating.

He said that he had contributed towards the payments for the apartment, but Ms Chua said the money was meant to go towards repaying the loans he took from her.

The judge ordered that the unit be sold and the proceeds be split, with 70 per cent going to Ms Chua and 30 per cent to Mr Chai, based on their purported contributions to the purchase of the property.